The Christmas feast stands or falls on its roast potatoes. If the turkey is a bit dry, you can slosh extra gravy on, and soggy sprouts are the sort of thing generations bond over. But potatoes that are anything other than cracklingly crisp, hot and golden, are a dinner disaster.
Ashley Palmer-Watts well understands the power of the roastie. The chef worked for 20 years under Heston Blumenthal, launched his two-Michelin-star restaurant Dinner, in London, in 2011, and oversaw the kitchen at Blumenthal’s Michelin-starred Hind’s Head in Bray.
But Sundays are spent cooking lunch (nine times out of 10 a roast chicken), for his wife, Emma, and children, Max and Sophia – and Palmer-Watts will be at the stove on Christmas Day as well.
Roast potatoes are always front and centre. “I am the most pedantic person about roast potatoes. I could talk all day about them,” he admitted to me when I visited the Fat Duck Experimental Kitchen, on an industrial estate near Maidenhead, in 2018.
Heston was not beetling around inside: he was in Provence for research, exploring the minerality of foods. But in the sleek grey and white test kitchen, the three clocks on the back wall showed the times in London, Melbourne and Dubai (there is a Dinner already in Melbourne, while the Dubai outpost is due to open next autumn). And it turns out time – and patience – are key components to the perfect roast spuds, which should have “a perfectly cooked inside and an almost glassy-crisp outside,” explained Palmer-Watts.
But before all that, the potatoes themselves need to be right. The best this month are Maris Piper, according to Palmer-Watts, but that will change through the year, as the level of sugar fluctuates with each variety during storage. Dry matter – the non-water part of the potato – also varies. Too much and the potatoes will fall apart when they are cooked, too little and they will be soggy.
I’ve always par-cooked my potatoes in fast-boiling water, so that the edges are crumbly but the inside is underdone. But that, Palmer-Watts told me, “is one of the key mistakes”. Instead, we need to be simmering them gently until they are cooked through.
“You want to remove as much water as possible, and cooking the potatoes dries them,” he explains. A dry inside is essential, since steam escaping from the inside of the spuds while they roast will stop the crust crisping up properly.
But hang on a minute, what do you mean cooking potatoes in water makes them drier? “Water will always migrate to a greater mass of water,” said Palmer-Watts firmly.
For this reason, he says, counter-intuitively, it’s better to boil the potatoes than steam them. The water needs to be salted, too – and not just for flavour. “It gives a crisp glassiness to the outside of the roast potato.”
After draining the potatoes, the chef advises, there’s no shaking them in the colander, as they should be falling apart a bit already, but they do need to cool, which will dry them even more.
Now, having created that perfectly cooked inside, it’s time to get the outside right. Palmer-Watts, to my surprise, glugged a mild extra-virgin olive oil into the tin. Isn’t it heresy to use extra-virgin oil at high heat? “I like it here. And you shouldn’t use a very high heat,” he explained. That’s especially important if you use duck or goose fat, which develops off flavours if the oven is too hot.
And talking of ovens, it’s important to know yours. “I’ve only got one oven at home,” Palmer-Watts cheerfully admitted, “and the front right-hand corner always browns food more quickly, so every time I take a tray out to baste, I turn it before it goes back in.” Everyone’s oven is different, so follow his instructions in the guide below, but tweak the timings and the temperatures to be perfect for you.
Back in the test kitchen, the smells of roasting Maris Pipers, garlic and herbs wafted around and I was beginning to understand why patience is key to good roasties.
“You can hear them,” Palmer-Watts finally announced, as he opened the oven to a distinct crackling, sizzling noise from the roasting tin. “Those are happy potatoes.” And not just the potatoes; hot, savoury, rich and crisp, these could be dish that makes dinner.
Ashley Palmer-Watts’s perfect roast potatoes
- For six people, peel 1.2kg Maris Piper potatoes (or the best, highest “dry matter” potato for the time of year). Cut the potatoes to create as many sides as you can, then rinse them really well in cold water to remove the starch.
- Half-fill a pan with cold water, adding 5g salt for every litre of water. Add the potatoes and bring to a simmer. Cook, without boiling hard, for 12-16 minutes, until the potatoes are cooked through – a thin-bladed knife should offer no resistance when pushed into the middle, and they should begin to crumble at the edges. Stir the pan three times, gently, during cooking.
- Drain well and lay them on a tray in a single layer to cool and dry. You can do this the day before: some grey patches may appear on the potatoes but they’ll vanish on roasting.
- Preheat the oven to 180C/160C fan/Gas 4. Pour 2-3 tbsp of olive oil into a roasting tin (25 x 35cm or similar). Sprinkle on a fat pinch of sea salt flakes. Arrange the potatoes in a single layer in the tin. Lay six cloves of unpeeled garlic on a board and bash gently with the flat of a knife, just enough to split the clove. Tuck the garlic cloves in among the potatoes. Trickle over another 4 tbsp olive oil. Sprinkle over another pinch of salt.
- Put the potatoes in the oven for about 30 minutes (if they were still hot when you put them in, open the door slightly for a second every five minutes to allow steam to escape).
- Take the tin out and turn the potatoes. If they stick, don’t force them: give them a bit longer. Baste them with the oil in the tin (adding more if you need to). If any of the garlic cloves are going black, fish them out. Return to the oven for another 20-30 minutes.
- About 10 minutes before the potatoes are ready, tuck in about six sprigs of rosemary and thyme, each about 4cm – the tender tops are more aromatic than the woody base.
- When the potatoes are done, they will be crisp and deep gold. Scatter with a few more herbs and grind over lots of black pepper. Tip on to a tray lined with kitchen paper to absorb any excess fat, then into a warmed bowl to serve.